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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Propofol (i.v. and i.p.) exhibited anticonvulsant activity in three models of seizure in the mouse, induced by bicuculline, kainic acid and N-methyl-DL-aspartic acid (NMDLA). Morphine, pethidine and fentanyl, which showed a biphasic dose-response relationship with respect to seizure modulation, abolished the anticonvulsant activity of propofol to exhibit their own intrinsic activity in proconvulsant doses. This occurred with very low doses of fentanyl and pethidine (15 micrograms kg-1 and 0.5 mg kg-1, respectively) in the NMDLA model. Thus it appears that propofol has anticonvulsant activity only when a convulsion is elicited directly; it does not prevent the actions of compounds that lower seizure threshold to convulsant stimuli. The anticonvulsant doses of morphine and fentanyl did not summate with the anticonvulsant activity of propofol. However, there was some evidence of summation of anticonvulsant activity between pethidine and propofol in the NMDLA model.
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PMID:Interactions between opioid drugs and propofol in laboratory models of seizures. 771 78

It is now clear that "seizure activity", excitatory phenomena, and/or a disorder of muscle tone are potential complications of the use of propofol. Whether this "seizure activity" is primarily, secondarily, or not at all a cerebral cortical event is still to be elucidated. Clearly propofol does have anticonvulsant activity, and also clearly it can produce an involuntary movement disorder, in certain patients, under certain conditions. Propofol is not the first anaesthetic drug to be implicated in the causation of seizures or abnormal movements nor indeed the first to appear to have anti-convulsant and proconvulsant activity (e.g. Althesin). While propofol has undoubtedly proved a very useful drug, the problem of convulsive phenomena creates a degree of background concern about its use. More needs to be known about the mechanism of this complication and any risk factors involved in determining who may have a seizure after propofol. In the clinical setting, the reporting of seizures possibly related to propofol should include--medical history, including personal or family history of epilepsy and movement disorders; a history of previous anaesthetics and whether propofol was used; regular medications; use of drugs or alcohol; history of chemical dependency; emotional state prior to induction; presence of hyperventilation or fever; a description of the alleged seizure, including rate of administration of propofol and amount given, time of onset of seizure in relation to time of drug administration, speed of onset of signs, quality of the abnormal movements, part of body involved, duration, any indication of a postictal state, any cardiovascular changes which may have accompanied the seizure, and any other possible triggers for the reaction such as other drugs used, including premedication; post seizure investigations including temperature, blood sugar, electrolytes, arterial gas analysis, neurological examination, EEG and CT scan. These actions and these investigations concerning propofol should not be delayed. It would appear appropriate to recommend to patients who experience apparent convulsive phenomena after propofol that they not be re-exposed to the drug.
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PMID:Propofol and seizures. 789 85

Propofol is a relatively new anesthetic agent used in outpatient surgery. Some investigators use it in the treatment of status epilepticus and in epilepsy surgery and have concluded that propofol has an anticonvulsant effect. Cases of seizure-like behaviors, myoclonus and opisthotonus following propofol anesthesia have been reported. Although rare, official warnings about this association have been issued. Different EEG abnormalities, and no abnormality, have been associated with propofol. We report a case of a healthy man who developed nonconvulsive seizures and generalized paroxysmal fast activity in his EEG following use of propofol for anesthesia.
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PMID:Propofol, seizures and generalized paroxysmal fast activity in the EEG. 808 14

The effects of the anesthetic agents propofol and methohexital on seizure duration, clinical outcome, recovery, and memory in electroconvulsive therapy (ECT) were studied in a double-blind trial. The study comprised 53 patients, 47 patients with major depression and six patients with other diagnoses according to DSM-III. Several recent clinical studies with a crossover design have shown a reduced seizure duration for anesthesia with propofol in comparison with both methohexital and thiopental. Propofol significantly reduced the seizure duration in this study without reducing the therapeutic outcome as measured by the Montgomery-Asberg Depression Rating Scale. Propofol did not significantly alter the length of the course of ECT; however, a slightly prolonged course for women cannot be completely ruled out. There were no significant differences between the two agents in effects on recovery times after anesthesia and on anterograde memory. In general, it seems that propofol is as effective as methohexital as an induction agent for ECT.
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PMID:A comparison of propofol and methohexital as anesthetic agents for ECT: effects on seizure duration, therapeutic outcome, and memory. 817 18

Propofol is a new, fast-acting intravenous (i.v.) anesthetic. Involuntary movements or epileptic seizures have occurred during or after propofol-induced anesthesia in approximately 50 reported cases; a third of the patients have had epilepsy. We report 5 patients with seizures in association with propofol anesthesia. A female epileptic patient developed severe status epilepticus; the other patients with short-lasting seizures had no previous epilepsy. Although propofol has been used in treatment of patients of status epilepticus, the risk of precipitation of epileptic seizures warrants consideration especially when planning anesthesia for epileptic patients.
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PMID:Seizures associated with propofol anesthesia. 840 33

Propofol is used widely during general anaesthesia but there has been concern that it may be implicated in provoking seizure activity. We have investigated the effects of low-dose propofol on the electrocorticogram of anaesthetized patients undergoing surgery for medically intractable epilepsy. During continuous peroperative recording of the electrocorticogram, propofol was administered in 25 mg increments until burst suppression occurred. Activation of the electrocorticogram occurred in 17 of 20 patients. There was an increase in mean spike frequency in 16, extension of spike distribution in 15 and polyphasia in 13 patients. The mean dose of propofol required to cause burst suppression was 88.2 (range 25-175) mg. We conclude that at low doses, propofol caused activation of the electrocorticogram in epileptic patients but at higher doses burst suppression was induced.
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PMID:Activation of the electrocorticogram by propofol during surgery for epilepsy. 865 19

This prospective study evaluated the effects of propofol sedation on the incidence of intraoperative seizures and the adequacy of electrocorticographic (ECoG) recordings during awake craniotomy performed for the management of refractory epilepsy. Thirty patients scheduled for temporal or frontal lobectomy for epilepsy under bupivacaine scalp block were randomized to receive patient-controlled propofol sedation (PCS) combined with a basal infusion of propofol (n = 15) or neurolept analgesia using an initial bolus dose of fentanyl (0.7 microg/kg) and droperidol (0.04 mg/kg) followed by a fentanyl infusion (n = 15). Propofol administration was suspended 15 min before ECoG recording in the PCS group. The occurrence of inappropriate intraoperative seizures was noted and, based on blind review, the adequacy of ECoG recordings was compared. A higher incidence of intraoperative seizures was noted among the neurolept patients (6 vs 0, P = 0.008). Intraoperatively, ECoG recordings were adequate to proceed with resection in both groups. Evidence of low spike activity on ECoG did not correlate with the type of sedation administered. Higher frequency background ECoG activity was noted among patients who received propofol, but this did not interfere with ECoG interpretation. The use of propofol sedation does not appear to interfere with ECoG during epilepsy surgery, provided administration is suspended at least 15 min before recording.
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PMID:Propofol sedation during awake craniotomy for seizures: electrocorticographic and epileptogenic effects. 917 7

The pro- or anticonvulsant properties of propofol remain a matter of controversy. Although numerous case reports describe the appearance of abnormal movements, posturing and seizure-like activity related to the use of propofol, systematic studies in both humans and animals strongly suggest that it possesses antiepileptic properties. Propofol consistently reduces the seizure duration during electroconvulsive therapy, its use has been successful in controlling refractory status epilepticus and in animals it offers a strong protection against lignocaine- or pentylene-tetrazol-induced epilepsy. The beneficial effects of propofol may be related to its uniform depressant action on the central nervous system, to a potentialization of GABA-mediated pre- and postsynaptic inhibition, and by decreasing the release of excitatory transmitters, glutamate and aspartate.
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PMID:Propofol: pro- or anticonvulsant? 920 33

Propofol is alleged to possess both pro- and anticonvulsant properties, leading to controversy regarding its use in patients with a history of seizures. Since propofol is administered for both sedation and hypnosis, it is important to understand the effects of low (0.5-1.0 mg/kg) and high (2-2.5 mg/kg) doses of propofol on the electroencephalogram (EEG). In this study, the hemodynamic and EEG effects of cumulative doses of propofol from 0.5 to 2.5 mg/kg i.v. were studied in 30 neurosurgical patients with or without a history of seizure disorders. While continuously recording from scalp EEG electrodes (F3, F4, C3, C4, P3, P4, O1, and O2), propofol 0.5 mg/kg was infused intravenously over 20 s. The same dose of propofol was reinjected four times at 2-min intervals, until a total dose of 2.5 mg/kg had been administered. The number and average amplitude of the EEG waves were counted and measured manually, respectively, from 80 to 90 s after beginning the injection of each dose of propofol. After lower propofol doses (0.5-1 mg/kg), the number of beta-waves increased, while alpha- and theta-waves decreased significantly in all patients. However, with larger doses of propofol (total dose of 2-2.5 mg/kg), the number of beta-waves decreased and delta-waves appeared. The amplitudes of all EEG waves increased and were maintained at a higher level after administration of propofol. Spike (or sharp) waves appeared in 33% of the control patients and in 40% of the epileptic group after propofol 0.5 mg/kg and in 73% of the control and 67% of the epileptic patients after the 1.5-mg/kg dose. In the majority of patients, the spike waves disappeared when additional doses of propofol were administered. One patient in the epileptic group had an EEG-recorded and clinical grand mal seizure after propofol 1 mg/kg, but the seizure disappeared after an additional 0.5-mg/kg bolus dose was administered. The propofol-induced EEG changes appeared initially at the frontal and central EEG electrodes and subsequently at the other EEG electrodes. Overall, there were no significant differences in the spectrum of EEG changes between the two patient populations. It is concluded that propofol produces similar dose-dependent effects on EEG activity in patients with or without a history of seizure disorders. While induction of anesthesia with higher doses of propofol (> 1.5 mg/kg) in neurosurgical patients with well controlled seizure disorder is safe, smaller sedative doses should be administered with caution to epileptic patients.
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PMID:Effect of sedative and hypnotic doses of propofol on the EEG activity of patients with or without a history of seizure disorders. 933 6

Propofol is a nonbarbiturate anesthetic induction agent known to have anti-convulsant properties. When used as an anesthetic for electroconvulsive therapy (ECT), it can reduce seizure duration to a significant degree, which may not be fully appreciated. A case is presented in which propofol caused a 63.1% reduction in mean seizure duration compared with preceding and subsequent treatments with thiopental anesthesia. The literature on the use of propofol for ECT was reviewed with specific reference to its effect on seizure duration and any evidence of superiority to the barbiturate induction agents. It is concluded that propofol may have only very circumscribed indications as an anesthetic for ECT. If used, psychiatrists and anesthetists must be aware of its potency as an anticonvulsant.
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PMID:Propofol anesthesia, seizure duration, and ECT: a case report and literature review. 964 6


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